Subthreshold characteristics of pentacene field-effect transistors influenced by grain boundaries.

Grain boundaries in polycrystalline pentacene films significantly affect the electrical characteristics of pentacene field-effect transistors (FETs). Upon reversal of the gate voltage sweep direction, pentacene FETs exhibited hysteretic behaviours in the subthreshold region, which was more pronounced for the FET having smaller pentacene grains. No shift in the flat-band voltage of the metal-insulator-semiconductor capacitor elucidates that the observed hysteresis was mainly caused by the influence of localized trap states existing at pentacene grain boundaries. From the results of continuous on/off switching operation of the pentacene FETs, hole depletion during the off period is found to be limited by pentacene grain boundaries. It is suggested that the polycrystalline nature of a pentacene film plays an important role on the dynamic characteristics of pentacene FETs

Stability Of contact discontinuity for steady Euler System in infinite duct

In this paper, we prove structural stability of contact discontinuities for full Euler system

Adhesion Induced DNA Naturation

DNA adsorption and naturation is modeled via two interacting flexible homopolymers coupled to a solid surface. DNA denatures if the entropy gain for unbinding the two strands overcomes the loss of binding energy. When adsorbed to a surface, the entropy gain is smaller than in the bulk, leading to a stronger binding and, upon neglecting self-avoidance, absence of a denatured phase. Now consider conditions where the binding potentials are too weak for naturation, and the surface potential too weak to adsorb single strands. In a variational approach it is shown that their combined action may lead to a naturated adsorbed phase. Conditions for the absence of naturation and adsorption are derived too. The phase diagram is constructed qualitatively.Comment: 4 pages, 1 figur

Room temperature spin coherence in ZnO

Time-resolved optical techniques are used to explore electron spin dynamics in bulk and epilayer samples of n-type ZnO as a function of temperature and magnetic field. The bulk sample yields a spin coherence time T2* of 20 ns at T = 30 K. Epilayer samples, grown by pulsed laser deposition, show a maximum T2* of 2 ns at T = 10 K, with spin precession persisting up to T = 280 K.Comment: 3 pages, 3 figure

Facile one-pot synthesis of dual-cation incorporated titanosilicate and its deposition to membrane surfaces for simultaneous removal of Cs⁺ and Sr²⁺

Selective removal of 137Cs and 90Sr from aqueous environments is essential for the volume reduction and ultimate safe storage of nuclear waste. This study introduces a facile one-pot hydrothermal synthesis of Dual-cation form of TitanoSilicate (DTS, M3HTi4O4(SiO4)3, M = Na+ and K+) for the effective and simultaneous removal of Cs+ and Sr2+. DTS showed enhanced adsorption capacities (469 mg/g for Cs+ and 179 mg/g for Sr2+) and the adsorption kinetics were extremely fast with around 98% and >99% removal achieved within 1 min from a dilute Cs+ and Sr2+ solution, respectively. Moreover, DTS indicated the superior selectivity for both Cs+ and Sr2+ due to the dual-cation incorporation in the structure. In groundwater, the distribution coefficients (Kd at V/m = 1000 mL/g) for DTS were high for both Cs+ (1 ppm, 2.9 × 105 mL/g) and Sr2+ (1 ppm, 1.0 × 105 mL/g), and even in seawater DTS maintained a Cs+ (1 ppm) Kd value as high as 4.9 × 104 mL/g. Remarkably, DTS is synthesized as a membrane with graphene oxide for continuous removal of the radionuclides, which is extremely beneficial to purifying a large volume of contaminated water

Fluorescence-Reported Allelic Exchange Mutagenesis Reveals a Role for \u3cem\u3eChlamydia trachomatis\u3c/em\u3e TmeA in Invasion That Is Independent of Host AHNAK

Development of approaches to genetically manipulate Chlamydia is fostering important advances in understanding pathogenesis. Fluorescence-reported allelic exchange mutagenesis (FRAEM) now enables the complete deletion of specific genes in C. trachomatis L2. We have leveraged this technology to delete the coding sequences for a known type III effector. The evidence provided here indicates that CT694/CTL0063 is a virulence protein involved in chlamydial invasion. Based on our findings, we designate the gene product corresponding to ct694-ctl0063 translocated membrane-associated effector A (TmeA). Deletion of tmeA did not impact development of intracellular chlamydiae. However, the absence of TmeA manifested as a decrease in infectivity in both tissue culture and murine infection models. The in vitro defect was reflected by impaired invasion of host cells. TmeA binds human AHNAK, and we demonstrate here that AHNAK is transiently recruited by invading chlamydiae. TmeA, however, is not required for endogenous AHNAK recruitment. TmeA also impairs AHNAK-dependent actin bundling activity. This TmeA-mediated effect likely does not explain impaired invasion displayed by the tmeA strain of Chlamydia, since AHNAK-deficient cells revealed no invasion phenotype. Overall, our data indicate the efficacy of FRAEM and reveal a role of TmeA during chlamydial invasion that manifests independently of effects on AHNAK